1. Technical Field
The present disclosure relates to a nonlinear distortion detection device that detects nonlinear distortion produced by a power amplifier used for a wireless communication device and the like and a distortion compensation power amplifier that is provided with the nonlinear distortion detection device.
2. Description of the Related Art
In recent years, mobile equipment equipped with a wireless communication function, such as mobile telephones and laptop personal computers, have been increasingly spread. In the wireless communication devices equipped in such equipment, there is a demand for high linearity in order to suppress an increase in adjacent channel leakage power derived from nonlinear input/output properties of a power amplifier. However, since it is difficult to attain higher output and higher efficiency while keeping high linearity, it becomes important to apply a nonlinear distortion compensation technique.
As an approach to compensate nonlinear properties of power amplifiers, a predistortion approach has been attracting attention in recent years. A predistortion approach is a method in which properties opposite to the distortion properties produced by a power amplifier are given to an input signal in advance to be inputted to the power amplifier. As a distortion compensation power amplifier using the predistortion approach, there is one described in Japanese Unexamined Patent Application Publication No. 2005-079935, for example.